Factual error: Special Duties Lysanders are shown operating from the same airfield as Lancaster Bombers. This never happened, they flew from RAF Tempsford in Bedfordshire. The bombers shown have the squadron code PD, these aircraft flew from RAF Waddington in Lincolnshire.
Factual error: The tailplane of the crashed German bomber is a HE177. The film is set in 1943, the HE177 didn't operate over Britain until 1944.
Other mistake: During the party at Max's house there is no black out despite an air raid going on. Light spills out of the house into the garden.
Factual error: There were no SS in North Africa, as shown iat the beginning of the film. There was a small SD office in Tunis. If there had been, SS would not have paraded around in Black, or normal field grey for that matter, they would have worn most likely a tropical uniform.
Character mistake: Max back in London is referred to as Group Captain, but his RAF Rank shows him as a Squadron Leader.
Plot hole: RAF airfields were heavily guarded, yet Max drives up to a Lysander with wife and child, gets in and starts it without anyone stopping him before help turns up.
Factual error: It is 1943, but the bathroom in which the pilot is throwing up is completely fitted with PVC drains and copper quick couplings. Neither existed at the time. (01:14:45)
Factual error: Max tells Marianne he plans to buy a ranch at the end of the war in Medicine Hat, Saskatchewan. Medicine Hat is in Alberta.